Using X-ray, infrared, and electron paramagnetic resonance methods, the reactivity of ZnO+xMn(2)O(3) systems during heat treatment was studied. Results showed that the solubility of manganese (Mn) in zinc oxide (ZnO) is lower than 3% and that reaction diffusion occurs. Reaction processes that take place in this system promote disintegration of Mn2O3 particles into microfragments and causes them to move along the surface of the ZnO particles (solid-state reactive wetting process).